The author of this article doesn't seem very keen on citations. I'd also like to know a related answer: are these two diameters the same because they're derive

The author of this article doesn't seem very keen on citations. I'd also like to know a related answer: are these two diameters the same because they're derived from the same model? Isn't the mass in the universe estimated from the observed diameter? Then take that mass and calculate the diameter of the hypothetical black hole with that mass, if the physics is the same, would that result back at the observed diameter of the universe? Or are these two completely separate models that just so happen to be similar and genuinely point to an insight?